Heavily used turf areas such as golf courses, athletic fields, parks, and recreational areas require regular maintenance to remain in good condition. Golf course fairways and, particularly, greens and tee areas are examples of turf that must be properly maintained to prevent severe and unacceptable degradation as the result of ordinary wear which in inherent in the intensive use to which such areas are subjected.
In order to promote vigorous growth necessary to maintain healthy turf, groundskeepers periodically aerate turf that is prone to becoming packed. Aeration is normally accomplished using either a spike aerator or, preferably, a core aerator drawn over the turf. The aerator makes a series of holes in the soil surface. It is beneficial to incorporate materials such as sand and/or peat into the soil, preferably by filling the holes made by the aerator. Sand, a sand/peat mixture, or other materials may be applied as a topdressing after aeration. After the topdressing material is distributed onto the turf, it must be incorporated into the soil to be effective; it is often worked into holes left by the aerator using brooms, rakes or similar tools.
Incorporating topdressing into the aerator holes manually is difficult and labor-intensive. There have been several previous attempts at developing machinery to assist in the task, but all have failed to satisfy fully the needs of groundskeepers. For example, U.S. Pat. No. 5,018,587 to Gandrud discloses a brush attachment for pulling behind a tractor. U.S. Pat. No. 4,989,676 to Rogers discloses a brush attachment adapted for pulling behind a mower for sweeping sand while mowing. Neither brush system is independently powered; therefore, the dispersal of sand is primarily in the direction of brush travel. A device manufactured by Smithco-Egandahl incorporates a ground-driven reciprocating assembly that imparts limited reciprocal motion to the brushes as it is drawn behind a tractor.
Because the previously known inventions move topdressing primarily in the direction of machine travel, it is often necessary to make multiple passes in order to sufficiently incorporate topdressing material into holes made by an aerator. Making multiple machine passes causes soil compaction, the very problem that necessitated the aeration procedure in the first place. In addition, dragging brushes linearly over turf can aggravate another problem, turf grain.
Turf grass can become aligned in one direction or take a set orientation in response to wear or machine travel. This set, or grain, can cause golf balls to roll differently in one direction compared to another and increase the tendency of the turf to mat down. Matted turf becomes disease-prone and is difficult to mow evenly.
What is needed is a system for efficiently and thoroughly incorporating topdressing materials into the holes formed by soil aeration without causing the turf to develop a grain. The present invention incorporates topdressing following soil aeration more quickly and more thoroughly than previously disclosed devices. In addition, the present invention is better adapted for raising matted grass to improve appearance, make mowing easier, and reduce turf damage caused by ordinary use.
The present invention is comprised of a frame extending between the motor vehicle to which it is mounted and casters opposite the motor vehicle. A deck is adjustably mounted to the frame. Synchronously counter-rotating brushes similar to the heads of stiff-bristled brooms used for sweeping shops, concrete floors, and sidewalks are mounted from the deck. Between two and twenty, preferably five, brushes are provided. The length and spacing of these rotary brushes are not critical and may be of any convenient dimensions. Rotary brush length is generally expected to be between one and three feet, preferably two feet, and may have a width of approximately four inches. Rotary brushes may preferably be spaced apart approximately 75% of the length of the individual rotary brush heads to provide overlapping brushing of turf. The preferred source of power for rotating the rotary brushes is an eight cubic inch hydraulic motor although other power sources are equivalent.
The rotary brushes are mounted to a deck resembling a conventional rotary mower deck. The invention is adaptable for mounting on triplex mowers in place of the usual front-mounted mower. The invention is adapted for optional mounting onto utility tractors, lawn and garden tractors, and other motor vehicles suitable for use on turf using two-point, three-point, and other hitch systems. Larger embodiments of the invention such as those using three-point hitch systems for attachment to utility tractors can readily be fabricated with the inclusion of additional rotary brush sets.
A hydrostatic drive motor, power take-off, electric motor, or auxiliary engine provides power for rotating the rotary brushes in a horizontal plane with the bristle ends in contact with the turf. A system of sprockets and chain is preferably used to transmit power from the power source to the rotary brushes. However, other power transmission equipment could be equivalently used to move the rotary brushes including belts, cog belts, gears, levers, cams, cranks, and the like. In cases where overlapping brushing is not wanted, synchronized brush rotation may not be required. The backs of the rotary brushes are attached to the lower ends of shafts which are turned by sprockets. A swirling pattern is described on the surface of the ground by the ends of the bristles as each rotary brush rotated about its vertical axis during use of the invention. The 360 degree movement of the bristles contacting the turf deflects and raises the leaves and stems of the vegetation and reduces the tendency of the grass to develop turf grain.
Casters permit the brushes to closely follow terrain contours by holding the deck at a constant height above the terrain. The deck depends from the frame by, preferably four, hangars and may be stabilized using drag links. Hangars may be adjusted by the operator to reduce or increase the pressure of the brushes against the turf. The adjustable hangars may be equipped with springs for biasing the deck upward to offset the downward pressure supplied to the brush bristles by the weight of the deck.
Optional transverse brushes or sweeps can provide improved brushing performance in some circumstances. The transverse brushes may be configured in any convenient layout, but preferably extend the full length of the brushing machine parallel to its longitudinal centerline which is also perpendicular to the normal direction of machine travel. Sweeps may be fixed to the deck or mounted using a floating mounting. Under some conditions transverse brushes may improve performance of the invention when used for incorporating topdressing.
Although the preferable motion of the powered brushes is described as rotary, orbital brush motion is equivalent to such rotary motion and may be incorporated in embodiments of the invention without departing from the scope of the disclosure. Suitable shields, guards and covers are included to protect the equipment and operators.
Additional advantages and features of the invention will become apparent from the following description of preferred embodiments made with reference to the accompanying drawing figures and claims which form a part of this specification.